Maize domestication in Central America

A study examines maize domestication in the Honduran highlands. Archeological and genetic evidence indicates that the domestication of maize (Zea mays ssp. mays) began in the Balsas region of Mexico by approximately 9,000 years ago. However, when maize became a staple grain in the Americas remains unclear. Douglas Kennett and colleagues report morphological characteristics of maize cobs found in the El Gigante rockshelter in western Honduras, which is outside the natural geographic range of Zea mays ssp. parviglumis, the wild predecessor of maize. Radiocarbon dates from 88 El Gigante botanical samples suggest that the rockshelter was used intermittently during the last 11,000 years. Direct radiocarbon dating of 37 cobs revealed that maize was abundant in deposits largely during two time periods: 4,340-4,020 years ago and 2,350-980 years ago. The earliest cobs had 10-14 rows, and the maize dating between 2,350 and 980 years ago exhibited increased cob and kernel size, compared with the older cobs. The data indicate that productive varieties of maize existed in Central America by approximately 4,300 years ago. Reproductive isolation outside the range of the wild predecessor may have aided the development of productive staple maize varieties, according to the authors.

Article #17-05052: “High-precision chronology for Central American maize diversification from El Gigante rockshelter, Honduras,” by Douglas J. Kennett et al.